The invention relates to a capped high-pressure discharge lamp comprising
a lamp vessel which is closed in a vacuumtight manner and has opposing first and second ends and an ionizable gas filling, and in which a pair of electrodes is arranged;
a first and a second current supply conductor which are connected to the pair of electrodes and which extend to the exterior from the first and the second end, respectively;
a lamp cap of insulating material mounted to the first end of the lamp vessel and provided with a first, central contact member which is connected to the first current supply conductor, and with a second contact member which is connected to the second current supply conductor.
The invention also relates to a lampholder for such a lamp.
Such a capped high-pressure discharge lamp and a lampholder suitable for it are known from EP 0 157 357 B1 which corresponds to U.S. Pat. No. 4,626,734.
Lamps of this kind are designed for use in scenic illumination when positioned inside a reflector, for example, for photo, film, or video shots. For that purpose, it is favourable if the reflector surrounds the lamp through a large solid angle, because in that case a large fraction of the generated light is concentrated into a beam.
The lamp cap of the known lamp has a laterally extending slot in which the second current supply conductor and the second contact member are eccentrically fixed with cement, laterally situated relative to the first contact member. The lamp cap as a result has a comparatively great lateral dimension and the reflector of the luminaire in which the lamp is to be used must have a comparatively great opening so that the lamp cap can be inserted through it into the lampholder arranged outside the reflector. This causes a loss in the beam concentration power of the reflector. Moreover, insertion of the lamp into the lampholder is difficult because the lamp cap must be accurately aimed during this in order to bring the second contact member into contact with the corresponding terminal of the lampholder.